The invention relates to an isolating device, in particular for an injection valve, with a turning spindle rotatably mounted in a device housing, actively connected to a drive device for the variable displacement of an operating element with an isolation stop valve connected to the turning spindle by means of a gearbox unit.
Such an isolating device is known from practice, and is, for example, operated via a handwheel or the like. By turning the handwheel the turning spindle is set rotating via a gearbox unit arranged between the handwheel and a turning spindle, and the operating element with the isolation stop valve is moved towards the injection valve or away from it together with the turning spindle. By the isolation stop valve, the injection valve can be closed or the passage thereof can be varied.
Corresponding isolating devices with hydraulic drive device are also known from practice. With these, corresponding feed or outlet lines for the hydraulic fluid to the isolating device, which are fixed to the device housing by means of corresponding connections, are necessary.
In particular in oil mining, the injection valve serves for injecting chemical substances which prevent that, for example, when the crude oil cools down when it is exiting the oil well, constituents of the crude oil solidify and possibly deposit in the conveying device. In an extreme case, the deposition of these solidifying substances can result in a seal of the conveying device. As oil is also extracted at places difficult to access, such as below sea level, the operation of isolating devices known from practice is difficult. For example, the manually operated isolating device has to be operated near the ocean floor by a diver or a corresponding submersible vessel. With such a manual operation, moreover a check of the setting of the isolating device and thus the closing of the injection valve is not sufficiently possible.
With the hydraulically operated isolating devices, it has to be noted that it is relatively complicated to supply them with hydraulic fluid and that corresponding connection lines have to be placed and connected to associated hydraulic fluid sources. If there is a leak at the corresponding hydraulic lines, the isolating device can no longer be correctly operated, and finding and repairing the leak is time-consuming and costly.